[basanti]

Hi. I installed the 30mm performance carb and the cone SB airfilter (i got off our hosts) and have the shorty exhaust on. Been trying dial in the correct air-fuel mixture and am a bit confused so took a pic of it to get a second opinion. I'm running 38 (or 45... i forget)  pilot jet and 138 main jet. The other jets i got with the carb kit are the 25 pilot jet and no. 132, 138, 140 and 142. The 25 pilot jet was way too lean and would not idle no matter what i tried.

Is this spark plug lean? It was rich off the throttle (the motor would try to die) and i adjusted it using the air screw, so that seems fine now. Off throttle and mid range feels strong now. At full wide open throttle when i hit 100-110 kms (max speed) it does some hiccupping. It doesn't seem to want to go above 100kms. Did the plug chop test and here is a pic. Should i try the 140 main jet?

Thanks in advance:)

[ace.cafe]

If it hiccups at full throttle, try  larger main jet.
You have to get the main jet working right at full throttle, and then fine tune the smaller throttle openings after that.

[basanti]

Thanks ace.cafe. Gonna try that today

[basanti]

I tried the size 138, and then 140 and then 142 and they all are doing the same thing: once the bike goes above 100 -105 km, the engine starts to hiccup. I do the plug chop thing and the spark plug is clean/white. The needle position is on the middle clip. At WOT that shouldn't make a difference, correct?

Any ideas what i could be doing wrong. A air leak? Visually i can't see anything wrong.

[ace.cafe]

Well, it sounds a bit odd.
I'd like it if somebody who owns and AVL that uses this carb would at least give us some idea of some jetting that works with it.

I'd try raising the needle higher.
I know on my Iron Bullet that I'm not anywhere near full throttle at 100km/h.

Perhaps an AVL owner could help us out with this.

[basanti]

When i get the time, I'm gonna check for air leaks.

Anyone who is using the 30mm performance carb with the S&B air filter, what jetting are you guys using. I'm running a shorty exhuast with the little perforated tube at the end of the bend pipe removed, and PAV blocked.

[chumma7]

You are still way lean on full throttle. Try jets larger than 142, then mess with your needle.

I went through a similar situation when I was testing velocity stacks. My main jet had to be raised from 230 to 290 (amal jets), which is a huge increase and at the time the largest jet I had was a 270. I just could not believe that I'd need any jet bigger than that so i figured there was a problem with the carb/air leak, piston issue, electrics issue... etc.